Study on the Effects of Reaction Temperature, Time and Stirring Rate on the Size and Dispersion of Nano-copper Powder

This paper systematically studies the liquid-phase reduction method for preparing nano-copper powder, aiming to solve the problems of difficult particle size control and easy agglomeration. By comparing three methods: direct reduction method (NMM), complex reduction method (CRM), and alcohol solvent reduction method (ARM), the effects of reaction temperature, reaction time, and stirring rate on the morphology, particle size, and dispersion of copper powder were systematically investigated. The results show that the alcohol solvent method and complex method are significantly superior to the direct reduction method in regulating particle size distribution and improving dispersion. Especially the alcohol solvent method, which uses glycerol as both the solvent and reducing agent, successfully prepares spherical nano-copper powder with an average particle size of about 200 nm and good dispersion, thanks to its slow reduction kinetics and excellent surface modification effect. This study clarifies the optimal process parameters for the three methods: NMM at 80 °C for 90 min with a stirring rate of 400 r·min-1, which can prepare copper powder with a particle size of about 300 nm; CRM at 90 °C for 90 min with a stirring rate of 300 r·min-1, which can prepare copper powder with a particle size of about 250 nm; ARM at 160 °C for 120 min with a stirring rate of 300 r·min-1, which can prepare copper powder with a particle size of about 200 nm. This provides a process reference for the controllable preparation of nano-copper powder.